Clousure System For Fuel Tank Filling Pipe

ABSTRACT

A closure system for the head of a fuel tank filling pipe, including: an essentially circular closure piece provided with a relief; and a moving part for (un)locking the closure piece by a rotational movement about the axis of the closure piece, the moving part including a relief configured to engage with the relief of the closure piece by a bayonet system. The reliefs are of a symmetrical shape allowing continuous rotation in both the clockwise and anticlockwise directions of the moving part relative to the closure piece.

The present invention relates to a closure system for a fuel tank filling pipe.

Filling pipes found on fuel tanks, particularly tanks carried in motor vehicles, are closed during normal use of the tank, when the tank is not being filled. The pipe is generally closed by a plug inserted into the top of the pipe with a rotary movement to close the pipe with a liquid- and gas-tight seal. Various kinds of metal and/or plastic plugs are found, being sealed by a seal created by screwing or turning a key inserted into the centre of the part external to the pipe.

The operations of removing the plug before filling the tank and replacing this plug and closing the pipe after filling it are usually done by hand by the user or by the employee of a filling station delivering the fuel. When tank filling is finished, the person may sometimes forget to replace the plug, thus resulting in the plug being lost and the pipe left open to the atmosphere for an indefinite period of time. During this period some of the liquid fuel may be lost and vapour may escape into the surrounding atmosphere.

To prevent plugs being lost and the atmosphere polluted, closure systems integrated into the filling pipe have been put forward as replacements for the traditional plug. The improved versions of these generally comprise fastening means for preventing the said systems opening accidentally, for example when the bowl (the depression in the bodywork, closed by the fuel flap, where the filling pipe is located) with a pressure washer.

For example, application WO 03/010022 in the applicant's name thus discloses a closure device with fastening means that can be disengaged by exerting pressure parallel to the axis of the pipe head, and are re-engaged automatically by the closure of the fuel flap. Such a system has the advantage of automatic locking coupled to the closure of the flap, and of being operational even if the vehicle's electrical system fails (disengagement being effected manually by the insertion of the nozzle). However, in such a system in which locking/unlocking is connected to the opening/closing of the flap by a system of links, the hinged flaps must have their hinge towards the front end of the vehicle (to assist automatic closure when the vehicle is being driven), which means that the direction of rotation of the bayonet depends on the side of the vehicle. Different parts therefore have to be provided depending on the model (some having the fuel flap on the left, others on the right), which doubles the tooling cost.

More sophisticated systems have also been put forward, in which the locking of the closure system can be independent of the locking of the flap. For example, application FR 04.13408 in the applicant's name relates to a closure system comprising a moving ring capable of preventing the movement of a closure piece by a bayonet system, and in which the movement between the opening and closing (or vice-versa) of the bayonet system is dependent on a dedicated actuator and consists of a progressive helical movement which progressively compresses (or decompresses) a seal placed between the closure piece and the pipe head. The drawback of such a system is that the closure piece moves in one direction for locking (compressing the seal) and in the other direction for unlocking (decompressing the seal), which complicates the mechanism of the system and also subjects the parts to localized wear, the helical movement generally occupying less than 360°.

The present invention solves the problems noted above by providing a completely symmetrical bayonet system, which can therefore be turned either clockwise or anticlockwise for locking (or unlocking) and even turned continuously, always in the same direction, from a locked position to an unlocked position of the system. It is therefore a sort of “universal” bayonet system (or reversible double bayonet), able to be turned continuously either clockwise or anticlockwise, opened by turning it left and closed by turning it right, or vice-versa.

To this end, the present invention relates to a closure system for the head of a fuel tank filling pipe, the said system comprising:

-   -   an essentially circular closure piece provided with a relief;         and     -   a moving part for (un)locking the closure piece by a rotational         movement about the axis of the closure piece, the said moving         part having a relief able to engage with the relief of the         closure piece by means of a bayonet system, the said reliefs         being of a symmetrical shape allowing continuous rotation in         both the clockwise and anticlockwise directions of the moving         part relative to the closure piece.

The expression “fuel tank” is used here to refer to any type of tank capable of storing a liquid and/or gas fuel under varying conditions of pressure and temperature. Of more particular interest are tanks of the type found in motor vehicles. The expression “motor vehicle” is intended to include cars, motor cycles and lorries.

The filling pipe is a pipe which communicates with the interior of the tank and allows fuel to be introduced.

The tank and the pipe may be made of metal or plastic.

The closure system of the invention is suitable for a tank and filling pipe assembly in which at least one of the two components of the assembly is made of plastic. It is particularly suitable for an assembly in which the filling pipe is made of plastic. This closure system itself preferably includes at least one plastic component. It is most particularly preferred for it to be made mainly of plastic.

The term “plastic” is used here to denote any material comprising at least one synthetic resin polymer.

All types of plastic may be suitable. Very suitable plastics belong to the category of thermoplastics.

The term “thermoplastic” denotes any thermoplastic polymer, including thermoplastic elastomers, and their blends. The term “polymer” denotes both homopolymers and copolymers (especially binary or ternary copolymers). Without implying any limitation, examples of such copolymers are: random copolymers, linear block copolymers, other block copolymers and graft copolymers.

Any type of thermoplastic polymer or copolymer whose melting point is below the decomposition temperature is suitable. Synthetic thermoplastics that have a melting range spread over at least 10 degrees Celsius are particularly suitable. Examples of such materials include those that exhibit polydispersion in their molecular weight.

In particular, polyolefins, polyvinyl halides, thermoplastic polyesters, polyketones, polyamides and copolymers thereof may be used. A blend of polymers or copolymers may also be used, as may a blend of polymeric materials with inorganic, organic and/or natural fillers such as the following non-exhaustive list: carbon, salts and other inorganic derivatives, and natural or polymeric fibres. In particular, polyamides filled with fibres (such as glass) are suitable. Advantageously, at least some of these polymeric materials contain a conductive filler (such as carbon black) to avoid problems with static electricity. It is also possible to use multilayer structures consisting of stacked layers bonded together, comprising at least one of the polymers or copolymers described above.

The purpose of the closure system according to the invention is to act as a plug that will seal the top of the filling pipe during periods when the tank is not being filled, in order to prevent any escape and loss of liquid fuel and vapour into the atmosphere if the tank contains fuel.

The closure system according to the invention is preferably integrated into the head of the filling pipe, that is to say, it is incorporated non-removably (in the sense that, unlike a plug, it does not have to be removed to gain access to the filling aperture, though it may of course be removed for repair or replacement) in an assembly of components all mounted on the top end of the filling pipe, their function being to guide a fuel dispensing nozzle and to facilitate filling. To this end, the pipe head comprises an aperture which communicates with (forms a continuation of) the filling pipe and which the closure piece of the system according to the invention seals shut when in the closed (locked) position.

The closure system according to the invention preferably enables automatic opening of the pipe through the action of a filling nozzle when it is in the unlocked position. The expression “automatic opening” means that the pipe is opened simply by the action of the dispensing nozzle, with no other mechanical intervention. The dispensing nozzle is of the type fitted to the hoses of fuel pumps in service stations.

The closure system includes a closure piece, meaning a device which closes the passage of gases and liquids through the abovementioned opening in the pipe head. This closure piece may take various forms, but according to the invention must be of essentially circular cross section. It is therefore a basically cylindrical part (that is, in the shape of a cylinder, with the exception of the relief of the bayonet) and may be elongate or flat (a disc). One suitable shape is the shape of a moving disc which blocks the passage when in the closed position. This disc preferably pivots about an axis. It is advantageously plastic but preferably has a metal cover, notably for reasons of appearance and abrasion-resistance (because of wear following repeated insertions of filling nozzles).

This disc may optionally be coupled to a rotary block comprising a cylindrical aperture (as in application FR 03.12782 in the applicant's name, the contents of which are introduced into this application by reference for this purpose).

This disc may also include a device for calibrating the pressure in the filling pipe and in particular a pressure/vacuum (SPD or Sécurité en Pression et Dépression) valve, as described in application FR 2753138, the contents of which are also introduced by reference into this application.

The closure piece is therefore preferably retractable when force is directed against it along an axis parallel to the axis of the pipe head. Various means may be present to make the closure piece retractable. One means that has given good results is a rod connected to the pipe head and fixed to the periphery of the closure piece, which can act as an axis of rotation to allow the closure piece to pivot. In this variant, the closure piece is preferably provided with means for attaching the rod to its perimeter.

The closure piece is kept closed by a restoring spring. A spring that is suitable is a torsion spring mounted around the rod with one end connected to the closure piece.

According to the invention, the closure piece is connected to a rotatable piece (which is preferably basically ring-shaped, and which for simplicity will hereinafter be referred to by the term “ring”) in a bayonet system, of which the engaging parts (the reliefs) are preferably situated, one on an inner surface (or, much preferred, on the perimeter of an inner aperture) of the ring, and one on the outer perimeter of the closure piece. These reliefs are preferably of a geometry that allows not only a rotary movement of the ring between the locked and unlocked positions of the bayonet, but also a “vertical” movement (parallel to the axis of the closure piece) of this ring for the compression/decompression of a seal situated between the closure piece and the pipe head or, more precisely, around the perimeter of the opening in the latter which the closure piece is designed to close. This seal may be of any kind. An O-ring seal gives goods results. The material of this seal will preferably be chosen to withstand fuel vapour. Fluorinated elastomers are suitable for this.

For example, one part (the ring, for example) may thus comprise cutouts suitable in number, size and shape for allowing the movement and passage of arms located on the other part (the closure piece). In particular, the cutouts in the ring (or in the closure piece) advantageously comprise a shelf and recesses corresponding in number, size and shape to the number of arms located on the closure piece (or on the ring). As a matter of very particular preference, the shelf and the arms are bevelled in a complementary manner, i.e. have a discontinuous relief such as to facilitate both their vertical and rotary movements.

In such systems, when the bayonet is in the locked position, the cutouts are engaged on a “horizontal” part (perpendicular to the axis of the closure piece and of the ring) of the shelf and immobilize the closure piece (pushing it along the axis does not allow it to pivot).

When the bayonet is being opened, the first movement imparted to the ring is a movement of rotation only, about the axis of the closure piece (describing for example at least ⅛, or ⅙, and preferably at least ¼ of a revolution (this fraction being in fact decided by the number of arms)), followed by a similar movement of rotation combined with a movement of translation parallel to this axis, for example about a few tenths of a millimetre, or even around 1 mm, depending on the nature of the seal (so that its compression is sufficient to achieve the desired leaktightness)) in a direction allowing decompression of the seal.

As a result, in this variant, the ramp comprises a repetition of flat profiles, rising ramps, descending ramps and recesses, in a defined sequence. The alternation (which is repeated a number of times equal to the number of recesses/arms) is preferably as follows: descending profile; flat profile; rising profile; recess (the rising direction being that which opens the device and decompresses the seal).

According to the invention, either the rotation of the ring is connected to the opening of the flap (e.g. by a system of links as described earlier), or it comes about by the intervention of a dedicated actuator. Any type of actuator is suitable for this purpose. A “manual” actuator (such as a lever, wire, ignition key, etc.) is one possibility. Another is an automatic (mechanical (motor), electrical or pneumatic) actuator.

If the rotation of the ring is connected to the opening of the flap, the bayonet ring generally moves in one direction to open, and in the opposite direction to close, the system according to the invention. If so, the ring need simply be provided with a drive tongue which can be connected to the fuel flap by a suitable mechanical link (a system of links, for example). This tongue is then subjected to a to-and-fro movement between a position in which the system is locked and a position in which the system is unlocked. The actual movement of the flap may be manual or electrical/mechanical (via a motor).

If the rotation of the ring is imparted by a dedicated actuator (independent of the fuel flap), this actuator is preferably also connected to a dedicated motor and may for example comprise a worm gear, and a pinion or rack system. In the case of pinion/rack systems, the ring is preferably provided with pinions (notches, teeth) on its outer perimeter.

In one particularly advantageous variant, and as described in application EP 2004/052157 in the applicant's name (the contents of which application are for this purpose incorporated by reference into the present application), the closure system according to the present invention also has a protective shield for the closure piece which is movable in basically the same plane, preferably basically at right angles to the axis of the pipe.

As a matter of decided preference, the said shield is movable by pivoting about an axis parallel to the axis of the pipe, in the same plane. Note that this variant also gives good results with other closure systems than those of the invention. Such a movement (of pivoting about an axis rather than of translation) allows the use of a protective shield of reduced size (a fraction of a slide), with its movement limited when compared with the complete slide (shield) system described in the abovementioned application (FIGS. 13 to 18). The result is a more reliable system with less friction-induced wear.

The present invention is illustrated, without any restriction being implied, in FIGS. 1 to 10.

FIGS. 1 and 2 illustrate 2 variants of the rotary piece (ring);

FIG. 3 illustrates a variant of the closure piece suitable for the two rings illustrated in FIGS. 1 and 2; and

FIGS. 4 to 10 illustrate a variant with an improved protective shield.

The ring shown in FIG. 1 comprises 3 recesses (1) and a shelf (2) in 3 parts each having an identical sequence: rising profile (3), flat profile (4) and descending profile (5). This ring has teeth (6) around its perimeter intended to mesh with mating teeth on an actuator (not shown). Such a system is suitable for continuous (360°) rotary operation, moving successively from a locked position (in which the arms of the corresponding closure piece lie on the flat profile (4) of the shelf) to an unlocked position (in which these arms are in the recesses (1)). This rotation can be either to the right or to the left because of the geometry of the ring.

The ring illustrated in FIG. 2 is identical to that in FIG. 1 except for the fact that the teeth (6) have been replaced by a drive tongue (7). Such a system is suitable for to-and-fro operation (between a locked position and an unlocked position as described above) and, therefore, for a system connected to the fuel flap which, because of its geometry, can be located either on the right or the left of the vehicle.

FIG. 3 shows a closure piece with arms (8) designed to engage with the shelf of a ring which may be as in FIG. 1 or as in FIG. 2. For this purpose, the arms are bevelled at their ends (9) to allow them to ride easily over the profile of the shelf and in particular to engage on and follow the different slopes of the shelf between two consecutive recesses, and so compress/decompress a seal (not shown). This closure piece also includes means (10) of attachment to a rod (hinge pin) connected to a pipe head (not shown); and a relief (11) providing a tight housing for a seal (also not shown) for preventing leakage between the closure piece and the orifice it is designed to close.

FIG. 4 is an exploded view of a variant of the invention with a pivoting protective shield. All the parts of the system may be distinguished, namely: a closure piece (1), a body (2) or support for a bayonet ring (3) designed to be connected to a slider (4), which in turn is designed to be connected to a hinge pin (5), which in turn is designed to be connected to a fuel flap (6). Also visible are a protective shield in the form of a fraction of a slide (7) and a restoring spring (8) for the said shield designed to be connected to a pushbutton (9) provided with a spring (10), besides a link (11) for respectively compressing and decompressing the spring (8). The other parts shown in this figure are for connecting/protecting the active components of the system (and consist in particular of: a cover (12); a filling bowl (13) fixed to the head by means of a fixing plate (14); and fixing means consisting of clips (15) and screws (16)).

FIGS. 5 and 6 are a general view of the closing/(un)locking system seen in the previous figure where the different components have been assembled, leaving out the parts relating to the protective shield, in order better to show how locking and unlocking take place. As can be seen in these figures, the head is locked and unlocked by means of the flap (6), the bayonet ring (3) being connected to the slider (4), which moves under the action of the flap (6) (opening/closing) via the hinge pin (5). FIG. 5 shows the locked position of the system and FIG. 6 the unlocked position.

FIGS. 7 to 12 show the operation of the protective shield, the movement of which is coupled to the (un)locking action described above.

FIGS. 7 and 8 show the system in the locked position with the protective shield on top; FIG. 9 shows the system in an unlocked position but with the protective shield still in place; FIG. 10 shows the system entirely unlocked and unprotected (shield retracted); and lastly, FIGS. 11 and 12 show how the system operates during locking.

In these figures it can be seen that the spring (8) is slightly compressed when assembled in the protective shield (7) in the locked position and retained by the button (9) (which has an index (17) inserted in a hole (18) in the shield (7)).

During unlocking, the slider (4) moves the link (11) and in so doing pulls (stretches, places under tension) the spring. Pressing on the button (9) releases the index (17) from the hole (18) in the protective shield (7). In so doing the shield is released and the spring (8) returns to its initial position, taking with it the protective shield (7) which advances until it meets the link (11).

During re-locking (shown in FIGS. 11 and 12), the flap (6) drives, via the connecting pin (5), the slider (4), which in turn drives the link (11), which pivots the protective shield (7) via the barrier (19) on the link, which compresses (places under tension) the spring (8). One end of the spring is fixed in a recess (20) in the cover (12), the other end being positioned in a recess (21) of the protective shield (7). The protective shield (7) slides over the index (17) of the button (9), which is mounted “flexibly” with a spring (22), and the hole (18) in the protective shield (7) engages on the index (17) of the button (9). 

1-10. (canceled)
 11. A closure system for a head of a fuel tank filling pipe, comprising: an essentially circular closure piece provided with a relief; and a moving part for (un)locking the closure piece by a rotational movement about the axis of the closure piece, the moving part including a relief configured to engage with the relief of the closure piece by a bayonet system, the reliefs being of a symmetrical shape allowing continuous rotation in both clockwise and anticlockwise directions of the moving part relative to the closure piece.
 12. The system according to claim 11, the system enabling automatic opening of the pipe through action of a filling nozzle when in the unlocked position.
 13. The system according to claim 12, wherein the closure piece is in a form of a moving plate pivoting about an axis.
 14. The system according to claim 11, further comprising a rod connected to the pipe head, fixed to a periphery of the closure piece and enabling the closure piece to pivot, the rod including a torsion spring with one end connected to the closure piece and enabling the closure piece to be kept in a closed position.
 15. The system according to claim 11, wherein the reliefs of the bayonet system are located in a first case on an inner surface of the rotary piece, which is in a shape of a ring, and a second case on a perimeter of the closure piece, and wherein the reliefs have a geometry that allows a rotary movement of the ring between locked and unlocked positions of the bayonet, and also allows a vertical movement parallel to the axis of the closure piece of the ring for compression/decompression of a seal situated between the closure piece and the pipe head.
 16. The system according to claim 15, wherein the closure piece comprises arms and the ring comprises a shelf and recesses corresponding in number, size, and shape to the arms of the closure piece, and wherein the shelf and the arms are bevelled in a complementary manner.
 17. The system according to claim 16, wherein the shelf comprises a repetition of a following alternation: descending profile; flat profile; rising profile; recess.
 18. The system according to claim 11, wherein the moving part comprises a drive tongue.
 19. The system according to claim 11, wherein the moving part includes teeth on its outer perimeter.
 20. The system according to claim 11, further comprising a protective shield for the closure piece, which is movable in a same plane by pivoting about an axis parallel to the axis of the pipe. 